VARIATIONS IN ANNULOPLASTY RING AND SIZER DIMENSIONS MAY ALTER OUTCOME IN MITRAL-VALVE REPAIR

Background and Aims: Sizing the mitral annulus remains one of the more subjective areas of annuloplasty surgery, We compared the dimensions of annuloplasty rings to annuloplasty sizers and to human mitral valve annuli to determine whether any discrepancies exist that might impact repair results, Methods: The anterior and posterior length of rigid r ings, flexible rings, and corresponding sizers were measured. The rati o of the anterior length to the total length was calculated (A/T ratio ) and compared to normal human ratios. Results: Nearly all rings had A /T ratios between 30% and 35% (except for the 32-mm rigid ring at 37.5 %), For both rigid and flexible rings, the ring A/T ratios and the siz er A/T ratios differed significantly (except for the 28-mm rigid ring and sizer), In comparison to the average human A/T ratio (36.6%), the ratio for most rings was significantly lower, Conclusions: The mismatc h between rings and sizers results in three possible scenarios: the le ngth of the anterior portion of the ring can be equal to, smaller than , or larger than the anterior portion of the sizer. The clinical impli cations are that the valve could become stenotic when the ring is impl anted or that the anterior portion of the annulus could be altered (st retched or buckled), We feel that to assure improved long-term results , more accurate matching of sizers to rings is essential and that bett er matching to normal human anatomical ratios would be ideal.